There are two different types of data sufficiency questions: one asks if there is sufficient information to determine the answer for a yes/no question, and one asks if there is sufficient information to determine the answer to a numerical question. Questions that ask for yes/no answers typically require a thorough understanding of fundamental math rules, while numerical questions will ask require a bit of calculation. It’s important to make the distinction between the two problem types because time is very limited on the exam, and it is easy to get sucked in to performing clock draining unnecessary calculations.

It’s also important to distinguish between yes/no and numerical question types to avoid careless errors. Data sufficiency questions will often ask for a yes/no answer, and it will provide a statement that requires a bit of calculation. You will obtain a “no” answer based on the statement, and this will tempt your gut instinct to write “no” because the answer to the statement is “no.” But remember, we aren’t concerned whether the answer to each statement is “yes” or “no,” all we are concerned with is determining if the information provided is sufficient, which in this case is “yes.” This is best explained in an example.